Recently the MacBook stopped working, constantly appearing the rainbow circle for long minutes as soon as I open an app or perform any action, reacting extremely slow. I formatted the hard drive and did a clean installation of the OSX El Capitan operating system 10.11.6, solving the problem momentarily, but the next day it had the same problems again. I did a check with Apple Hardware Test (complete) and no errors were found. Perform a hard disk check through Disk Utility and no errors were found. Start with Safe Start mode and everything works relatively well (I'm here at the moment, but it also freezes sometimes, but the reaction time is less than normal startup), clean cache, take out the items to log in, delete items de Librería / StartupItems, ~ Library / LaunchAgents, Library / LaunchAgents, Library / LaunchDeamons (none had to do with OSX, almost all were from Adobe, and one from Utorrent)
After doing all this in normal startup mode, you still have problems with any activity, and only run "smoothly" in safe boot mode.
If someone can give me some idea of what other actions to do to solve this problem, I would be very grateful, because I urgently need it to be operational again. To expand the idea of use, I work a lot with After Effects, Final Cut, Photoshop, Illustrator and Logic. It always worked excellent with all the programs. It's a Macbook Pro 13 'mid 2012 4 GB RAM